[Supras] Hopefully useful ARP head stud information

[berniek at technicaldevelop.com]

During installation of a Cometic HG, I learned a few things which may be 
of assistance to those who have not dealt with ARP head studs before:

1.  Always thread the studs into the block with the 3/16 hex depression 
in the top.  That way they can be removed if needed.

2.  The socket to fit the nuts requires machining unless there exists a 
special socket I could not find.  I got a Sears 12 point 14 mm 1/2" 
drive socket, number 44444, the heaviest they had.  To clear the bucket 
housings, camshafts and center valley wall, the socket had to be 
machined as follows:

a.  For the first .740" of the length starting from the nut end, reduce 
the diameter to .765".  That involves removal of about .015" to.020" 
from the business end of the socket.  It will be necessary to use a 
carbide bit in the lathe.  The socket is of high quality, made from 
tough steel.  The surface finish will not be spectacular, but such is 
the price of machining hard steel without more involved finishing 
techniques. 

b.  Then reduce the diameter towards the drive end to .735" for  a 
further length of 1.650".  So the total machined length from the nut end 
will be 1.650' + .740" = 2.390".   That reduced diameter is to clear the 
camshafts and center valley wall.  There is plenty of meat in the socket 
wall once above the 12 point end, so no real  weakness will exist.  Do 
not go further back in machining or you will cut through to the corners 
of the 1/2" drive recess. 

3.  Set the camshafts both so the TDC marks are upwards.  All nuts will 
then be accessible past camshaft bumps, hex sections, etc. 

4.  The washers MUST be installed on the head surface before the studs 
are installed.  They will not fit the studs afterwards due to the bucket 
housing wall thickness. 

5.  Using the moly lube supplied by ARP, torquing to 80 lb-ft.  was no 
problem, done in four stages.  The socket held up perfectly. 

6.  If you have had the head and rear timing cover decked (necessary 
with any MHG, the ends of the gasket pieces will stick up above the head 
surface.  They must be cut off flush since the gasket covers that junction.

7.  It may be possible to carry the nut end diameter to .765" before 
carrying it back to .740" diameter section  However, that will weaken 
the socket at its must vulnerable point, the nut end where the wall is 
thinnest. 

    Hope this of some use.

       BernieK